Hi,
that was pretty simple. After I switched to the new theme and updated the plugins I just had to do some small adjustments. Now my site is up-to-date. Very nice. Thank you.
Angulus
I can use just one menu. It would be good to use different menues on defferent pages. But in the menu configuration is this note: Your theme supports 1 menu. Select which menu you would like to use.
The Avada WP theme supports 3 menus.